Cutting and Threading Aluminum

So I have two main requirements for what I need to do with my MPCNC. I need to be able to cut 10mm thick aluminum. I have almost no idea what kind of router bit I will need to do this, and I also don’t know what modifications I will need to do to my future MPCNC. What I do know, however, is that my MPCNC will only be 20" by 30" which I believe would make it fairly sturdy. I am also using 84oz/in steppers, but I don’t know whether that makes a difference with cutting aluminum.

The second requirement that I have is that I need to thread tap holes that are 10mm deep. I have some m4 screws that I would like to be able to thread tap for. I also have no idea what kind of router bit that I would need. What I do know is the basic knowledge of how to do it in ESTLCAM (Thank god for the tutorial videos that he provided). I know that I would have to cut a regular hole first, then go in with some kind of thread bit. What I don’t know is what kind of bit I would need and also whether the MPCNC can even achieve this.

Any help is appreciated, thanks.

Cutting area or outside dimensions? That is a very large cutting area for metal. But outside dims, that would be excellent.


Nope, heavier so your accelerations will need to be a bit slower.

You can drill the holes but automating the tapping part probably isn’t going to happen.


Is your goal some sort of production? This is really good for prototyping in all materials up to aluminum and brass, but production in metal is not a good idea depending on how you value your time.


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Unless you are trying to tap really large holes, then you can mill with a tapping bit but I have never tried that and I would guess the holes would have to be 30mm plus.

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The outside dimensions are 20" by 30". Sorry I didn’t clarify that! With ESTLCAM I believe you can tap holes by setting a hole size and depth then do a tool change and go in with a thread bit. My main question is what bits will I need to do this kind of work? I know I will need something with one flute but other than that I am lost. And with the threading bit I have no idea whatsoever.

And yes I am looking to do production. The main plan is to have this running for a good bit and make the same part over again in aluminum, acrylic, and wood. I run a very small PC Customs shop and I am looking to make something similar to this:

My main problem is just knowledge and budget. And thank you for replying super fast!

Tapping with a cnc seems like a lot of work… You’d have to set a reasonably slow rpm along with a slow feed, getting those to match might be pretty difficult.

I think it would be much easier to cnc the holes then tap them with a battery drill with the clutch set very low.


Breaking taps sucks too!

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I have done almost exactly what you plan on doing and…just tap them by hand honestly. I “produce” with this machine on a daily basis on aluminum but no longer tap holes as I changed the design to use nylon locknuts.

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So would something like this cut Aluminum well? I guess I will tap by hand now so all I need to find is a bit that will cut aluminum well.

There is a attachment for using taps on a CNC but I doubt it would work on these types of machines and definitely not worth the hassle.

If you can use any other material than aluminum you will have a much easier time, and produce parts much faster. If it does have to do with wires metal is not a good choice. you will need to tumble them or break all the edges as well as tapping. The cost will be really high per part.

Here is how you do larger holes.

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Yes that was the tutorial video I was talking about. I bet this could be scaled down to make m4 holes but it would be hard as yall said it would.

And the wires that are using in PC Build usually have a thick jacket and these parts are meant to be used with wires that have PET Sleeving on them or Paracord Sleeving. Using a conductive or sharp metal is not the problem imo. I guess the only way to really know whether this can work is to actually try it out, but then again I don’t really want to waste money to have a broken bit.

No way you are going to get an m4 out of that. See what thread cutting bits you can find but I would say M8 would be pushing it.

If you look at Kevin’s thread we all have lots of suggestions for tapping holes and CNC isn’t one of them.—Threading/Browse-Our-Products_271/Thread-Milling-Cutters—Single-Form_157.aspx

Crazy small bits if I am reading their stuff correctly. Perhaps this could work? One problem I see is getting the tool bit into the hole.

I would love for you to try it. I don’t think it will work but if it does that would be awesome.

There is absolutely no point whatsoever in taping holes with a CNC, unless it is very big holes.

Manual tap takes no time on aluminum, the best way is to use a drill press to make sure you are perpendicular, but it can also be done just with bare hands with a bit of practice.

For 10mm aluminum, I’d do taps using a portable drill, it’s soft enough so that a 4mm tap can take it in 2 or 3 passes.

That would be amazing to see a vid of if it works.!